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<title>Berkeley DB Reference Guide: Flushing the database cache</title>
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<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></b></td>
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<p align=center><b>Flushing the database cache</b></p>
<p>The <a href="../../api_c/db_sync.html">DB-&gt;sync</a> method flushes all modified records from the database
cache to disk.</p>
<p><b>It is important to understand that flushing cached information
to disk only minimizes the window of opportunity for corrupted data, it
does not eliminate the possibility.</b></p>
<p>While unlikely, it is possible for database corruption to happen if a
system or application crash occurs while writing data to the database. To
ensure that database corruption never occurs, applications must either:</p>
<p><ul type=disc>
<li>Use transactions and logging with automatic recovery.
<li>Use logging and application-specific recovery.
<li>Edit a copy of the database, and, once all applications
using the database have successfully called <a href="../../api_c/db_close.html">DB-&gt;close</a>, use
system operations (for example, the POSIX rename system call) to
atomically replace the original database with the updated copy.
</ul>
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